class Settings():
"""存储《外星人入侵》的基本参数"""
def __init__(self):
"""初始化游戏的设置"""
#屏幕设置
self.screen_width = 1200
self.screen_height = 700
self.bg_color = (230,230,230)
self.ship_speed_factor = 1.5
self.ship_limit = 3
#子弹参数配置
self.bullet_speed_factor = 1
self.bullet_width = 3
self.bullet_height = 15
self.bullet_color = 60, 60, 60
self.bullets_allowed = 3
#外星人参数
self.alien_speed = 1
self.fleet_speed = 10
self.fleet_direction = 1
import pygame
class Ship():
def __init__(self, set, screen):
self.set = set
self.screen = screen
#导入图片，获取图片所在矩形宽、高
self.image = pygame.image.load('images/ship.bmp')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
#设置飞船放在屏幕底部中央
self.rect.centerx = self.screen_rect.centerx
self.rect.bottom = self.screen_rect.bottom
#在飞船的属性centerx修改为浮点，便于小数运算
self.center = float(self.rect.centerx)
#移动标志
self.moving_right = False
self.moving_left = False
def center_ship(self):
"""将飞船放在中央"""
self.center = self.screen_rect.centerx
#更新飞船坐标
def update(self):
if self.moving_right and self.rect.right < self.screen_rect.right:
self.center += self.set.ship_speed_factor
if self.moving_left and self.rect.left > 0:
self.center -= self.set.ship_speed_factor
self.rect.centerx = self.center
def blitme(self):
#指定位置绘制飞船，两个参数，绘制的图片Surface、画的位置dest
self.screen.blit(self.image,self.rect)
import pygame
from pygame.sprite import Sprite
class Alien(Sprite):
"""创建一个外星人类"""
def __init__(self, set, screen):
"""始化外星人并设置起始位置"""
super(Alien, self).__init__()
self.screen = screen
self.set = set
#加载图片，并设置rect属性
self.image = pygame.image.load('images/alien.bmp')
self.rect = self.image.get_rect()
#外星人位置为左上角，left=x,top=y
self.rect.x = self.rect.width
self.rect.y = self.rect.height
#浮点化，便于运算
self.x = float(self.rect.x)
def check_edges(self):
"""检查外星人是否到达屏幕边缘"""
screen_rect = self.screen.get_rect()
if self.rect.right >= screen_rect.right:
return True
elif self.rect.left <= 0:
return True
def update(self):
"""左右移动外星人"""
self.x += (self.set.alien_speed *
self.set.fleet_direction)
self.rect.x = self.x
def blitme(self):
"""制定位置绘制外星人，两个参数，绘制的图片Surface、画的位置dest"""
self.screen.blit(self.image, self.rect)
import pygame
from pygame.sprite import Sprite
class Bullet(Sprite):
def __init__(self, set, screen, ship):
"""创建一个管理子弹的类"""
super().__init__()
self.screen = screen
#在（0,0）位置画矩形子弹，然后设置子弹位置
self.rect = pygame.Rect(0, 0, set.bullet_width,
set.bullet_height)
#X坐标等于飞船X中间，Y坐标等于飞船top的Y坐标
self.rect.centerx = ship.rect.centerx
self.rect.top = ship.rect.top
#小数化Y坐标，便于移动运算
self.y = float(self.rect.y)
#子弹颜色、速度
self.color = set.bullet_color
self.speed_factor = set.bullet_speed_factor
def update(self):
"""向上移动子弹"""
# 更新子弹Y坐标.
self.y -= self.speed_factor
self.rect.y = self.y
def draw_bullet(self):
"""将子弹画在屏幕上"""
pygame.draw.rect(self.screen, self.color, self.rect)
功能实现 game_functions.py
import sys
from time import sleep
import pygame
from bullet import Bullet
from alien import Alien
def check_keydown_events(event, set, screen, ship, bullets):
"""响应按键"""
if event.key == pygame.K_RIGHT:
ship.moving_right = True
elif event.key == pygame.K_LEFT:
ship.moving_left = True
elif event.key == pygame.K_SPACE:
fire_bullet(set, screen, ship, bullets)
elif event.key == pygame.K_q:
sys.exit()
def check_keyup_events(event, ship):
"""响应按键松开"""
if event.key == pygame.K_RIGHT:
ship.moving_right = False
elif event.key == pygame.K_LEFT:
ship.moving_left = False
def check_events(set, screen, ship, bullets):
"""响应键盘、鼠标事件"""
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
check_keydown_events(event, set, screen, ship, bullets)
elif event.type == pygame.KEYUP:
check_keyup_events(event, ship)
def fire_bullet(set, screen, ship, bullets):
"""没有超过限制就创建一个子弹，并且加入子弹组"""
if len(bullets) < set.bullets_allowed:
new_bullet = Bullet(set, screen, ship)
bullets.add(new_bullet)
def update_screen(set, screen, ship, aliens, bullets):
"""更新屏幕图像，显示新的图像"""
# 每次循环时重新绘制屏幕
screen.fill(set.bg_color)
#画出所有子弹，在飞船、外星人的后面
for bullet in bullets.sprites():
bullet.draw_bullet()
ship.blitme()
aliens.draw(screen)
#让最近的绘制可见
pygame.display.flip()
def update_bullets(set, screen, ship, aliens, bullets):
#更新子弹
bullets.update()
#删除消失的子弹
for bullet in bullets.copy():
if bullet.rect.bottom <= 0:
bullets.remove(bullet)
check_bullet_alien_collisions(set, screen, ship, aliens, bullets)
def check_bullet_alien_collisions(set, screen, ship, aliens, bullets):
"""检查子弹外是否击中外星人"""
#删除相遇的子弹，外星人
collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)
if len(aliens) == 0:
#删除现有子弹，创建新的一群外星人
bullets.empty()
create_fleet(set, screen, ship, aliens)
def check_fleet_edges(set, aliens):
"""有外星人到达边缘后，改变方向"""
for alien in aliens.sprites():
if alien.check_edges():
change_fleet_direction(set, aliens)
break
def change_fleet_direction(set, aliens):
"""将外星人下移，并且改变运动方向"""
for alien in aliens.sprites():
alien.rect.y += set.fleet_speed
set.fleet_direction *= -1
def ship_hit(set, stats, screen, ship, aliens, bullets):
"""响应飞船被撞到"""
if stats.ships_left > 0:
#生命值减去1
stats.ships_left -= 1
else:
stats.game_active = False
#清空子弹、外星人
aliens.empty()
bullets.empty()
#新建一群外星人、将飞船放在中央
create_fleet(set, screen, ship, aliens)
ship.center_ship()
#暂停一下
sleep(0.5)
def check_aliens_bottom(set, stats, screen, ship, aliens, bullets):
"""检查是否有外星人到达了屏幕底端"""
screen_rect = screen.get_rect()
for alien in aliens.sprites():
if alien.rect.bottom >= screen_rect.bottom:
#想飞船相撞一样处理
ship_hit(set, stats, screen, ship, aliens, bullets)
break
def update_aliens(set, stats, screen, ship, aliens, bullets):
"""检查是否到达屏幕两边"""
check_fleet_edges(set, aliens)
aliens.update()
# 检测外星人和飞船碰撞
if pygame.sprite.spritecollideany(ship, aliens):
ship_hit(set, stats, screen, ship, aliens, bullets)
# 检查是否有外星人到达屏幕底端
check_aliens_bottom(set, stats, screen, ship, aliens, bullets)
def get_number_aliens_x(set, alien_width):
"""计算一行能有多少外星人"""
available_space_x = set.screen_width - 2 * alien_width
number_aliens_x = int(available_space_x / (2 * alien_width))
return number_aliens_x
def get_number_rows(set, ship_height, alien_height):
"""计算有几行外星人"""
available_space_y = (set.screen_height -
(3 * alien_height) - ship_height)
number_rows = int(available_space_y / (2 * alien_height))
return number_rows
def create_alien(set, screen, aliens, alien_number, row_number):
"""创建外星人"""
alien = Alien(set, screen)
alien_width = alien.rect.width
alien.x = alien_width + 2 * alien_width * alien_number
alien.rect.x = alien.x
alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
aliens.add(alien)
def create_fleet(set, screen, ship, aliens):
"""创建外星人群"""
#导入参数，获取一行几个，有几行
alien = Alien(set, screen)
number_aliens_x = get_number_aliens_x(set, alien.rect.width)
number_rows = get_number_rows(set, ship.rect.height,
alien.rect.height)
#创建外星人
for row_number in range(number_rows):
for alien_number in range(number_aliens_x):
create_alien(set, screen, aliens, alien_number,
row_number)
计分 game_stats.py
class GameStats():
"""跟踪统计游戏信息"""
def __init__(self, set):
"""初始化游戏的统计信息"""
self.set = set
self.reset_stats()
#游戏刚启动时处于活动状态
self.game_active = True
def reset_stats(self):
"""初初始化在游戏中可能变化的统计信息"""
self.ships_left = self.set.ship_limit
主函数
import pygame
from pygame.sprite import Group
from settings import Settings
from game_stats import GameStats
from ship import Ship
import game_functions as gf
def run_game():
#初始化pygame、设置屏幕对象
pygame.init()
set = Settings()
#初始化屏幕大小参数
screen = pygame.display.set_mode(
(set.screen_width, set.screen_height)
)
#设置标题
pygame.display.set_caption("大战外星人")
stats = GameStats(set)
#设置背景颜色
bg_color = (230,230,230)
#画飞船
ship = Ship(set,screen)
#创建子弹组
bullets = Group()
aliens = Group()
#创建外星人群
gf.create_fleet(set, screen, ship, aliens)
#游戏主循环
while True:
#监视键盘鼠标事件
gf.check_events(set, screen, ship, bullets)
if stats.game_active:
ship.update()
gf.update_bullets(set, screen, ship, aliens, bullets)
gf.update_aliens(set, stats, screen, ship, aliens, bullets)
gf.update_screen(set, screen, ship, aliens, bullets)
run_game()